S4 SE Polarity

[matt1954]

Hi
I'm in the process of a complete rebuild of my 1970 Elan S4 SE. I took the car apart many years ago and always thought it was positive earth (I don't know what I based that on). However, on looking at the wiring diagram for a Lotus Elan 4 in the workshop manual I see that the earth is shown as negative. I had the bare engine running late last year and temporariy wired it as if it were positive earth and it went well but that doesn't mean that's right. Is there a simple answer to this, were all S4s negative earth? I know there could be a problem with the tacho and coil and possibly the dynamo if I get it wrong. Is there any other way of telling what it should be?
Cheers
Matt

[types26/36]

Have a close look at your tacho, it normally says on it if its pos or neg earth.

[Mazzini]

The S1-3 were positive earth and the S4 and Sprint were negative earth.